Door lock



June 14, 1966 T. HERMANN 3,255,618

DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 1 :2 I INVENTOR.

TOBIAS HERMANN ATTORNEYS.

June 14, 1966 1'. HERMANN 3,255,618

DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 2 INVENTOR. TOBIAS HERMANNA T TOR NE Y1 June 14, 1966 T. HERMANN 3,255,618

DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 3 FIG. 5 fg gz A TTOR NEY5:

T. HERMANN June 14, 1966 DOOR LOCK 4 Sheets-Sheet 4 Filed April 22, 1964FIG] ATTORNEYS.

United States Patent 3,255,618 DOOR LOCK Tobias Hermann, Burlington,Iowa, assignor of fifty percent to Gerard B. McDermott, Burlington, IowaFiled Apr. 22, 1964, Ser. No. 361,848 14 Claims. (Cl. 70-114) Thisinvention relates to a lock particularly suited for doors and otherclosure members and other closure memhers and more particularly to aso-called security lock for reducing the possibility of unauthorizedentry and which is less susceptible to tampering, especially from theoutside of the door.

While no door lock is completely burglar proof, certain types of locksare more resistant to tampering and make unauthorized entry moredifficult. Locks especially designed for this purpose are often referredto as security locks in that they provide maximum security fromunauthorized entry to a room or container which they protect.

A wide variety of security locks have been proposed in the past offeringvarious degrees of protection from different types of burglarization,depending upon the particular use and application of the closure deviceto which they are affixed. However, many of these locks are difficult tooperate in that they have a tendency to bind, in some instances aresubject to excessive wear, and very often do not provide the tamperresistance to unauthorized entry or burglarization intended.

The present invention provides a novel security type door lockovercoming many of the above disadvantages. It is intended to providemaximum security from outside entry and limited security from insideattack. At the same time the lock is readily adaptable to a wide varietyof door types and constructions and is useable with double doors, woodor metal, inswing or outswing, single doors of this nature and evenoverhead or lift doors with the lock and bolts mounted in a horizontaldirection. Likewise, a wide variety of locking arrangements may be usedin conjunction with the lock of this invention including single anddouble custody arrangements, used in conjunction with various key andhandle combinations.

Most locks using vertical locking bars of the type under considerationcan be fairly easily burglarized by breaking off the outside handle anddriving the conventional handle shaft through the door. Such action willvary often release the locking bars, or if not, will expose an actuatingtube having a central aperture of rectangular cross-section to which aniron bar or other strong instrument may be applied to force the lock.Tampering of this type will not open or seriously damage the lock of thepresent invention since provision is made for the support of a bolt camplate by a central .circular tube with the plate held in position by aspacer welded to the tube. The bolt bars are held in position on camplate studs by cotter keys so they can not be jarred off. Actuation ofthe bolt bars is by way of an apertured lever slidable over a pair ofpins rotatably received by the locking bars. Thus, breaking oif thehandle and driving out the handle shaft through the door removes alldirect coupling to. the locking bars without at the same time releasingthe bolts so that nothing is accessible from the exterior of the door bymeans of which the locking bars or bolts may be forced.

Locks and cam plate are mounted on a single piece of metal in the formof a lock mounting plate .so that one may not be moved out of alignmentwith the other. The lock mounting plate is fastened to the inside of thedoor by a plurality of screws several of which are located behind thecam plate so they cannot be easily removed when the camplate is in thelocked position. One or more Patented June 14, 1966 cylinder locks arefastened to the lock mounting plate by socket head screws which cannotbe removed with a screwdriver.

The entire assembly is constructed of heavy gauge metal to resist wearand abuse, all joints are welded, and the supporting tube for the camplate extends through the door so that pulling on the inside handle whenclosing the door does not crush the door material which is possible whenthe lock is used on wood or hollow core metal doors. Heavy locking barsare provided and are in vertie cal alignment when the device is in thelocked posit-ion to provide a complete deadlock and ready visualindication of the locked condition. Bolt brackets are providedpreferably having a shield holding the bars away from the door and thuslimiting wear on the door by movement of the locking bars.

If the outside handle is broken off or dismantled in a burglary attemptthe cam plate and bars are held in locked position. The outside rim ofeach cylinder lock is screwed directly -to the mounting plateeliminating the possibility of turning the cylinder in the door tounlock it. In the preferred embodiment the bar bolts are provided withapproximately l /z inches of throw to completely eliminate prying.

It is therefore one object of the present invention to provide a noveldoor lock.

Another object of the present invention is to provide a security typedoor lock.

Another object of the present invention is to provide a lock givingmaximum security from outside entry and limited security from insideattack.

Another object of the present invention is to provide a door lock for awide variety of doors of relatively simple construction, easy tooperate, and one which is not seriously affected by excessive wear.

Another object of the present invention is to provide a novel securitylock embodying a complete deadlock, with the position of the lock barsgiving an instantaneous visual indication ofwhether the bolts are in thelocked position, that is they are straight when locked, and staggeredwhen unlocked.

Another object of the present invention is to provide a door lockwherein the handle mechanism is so constructed as to be completelyremovable from the cam plate without affecting locking operation of thedevice. If enough turning pressure is applied to the outside handle, orthe inside handle, while .the device is in locked position, the handlewill break free from the cam control bar or lever (which bar is weldedto the handle and engages the cam bolt stud pins) or twist off beforethe cam plate can be forced into unlocked position. In other words, thedevice is designed to withstand the twisting off and complete removal ofthe handle without causing a successful entry by force. In addition, theoutside rim cylinder is held in position by retaining screws which passcompletely through the mounting plate. The lock cylinder is thereforefastened directly to the lock mounting plate thus minimizing the dangerof twisting the cylinder FIGURE 4 is an inside elevational view of asingle custody lock similar to that of FIGURE 1;

"FIGURE 5 is a view similar :to that of FIGURE 4 showing the device inthe unlocked position;

FIGURE 6 is a horizontal section through the lock and door of FIGURES 4and 5;

FIGURE 7 is a vertical section through the lock; and

FIGURE 8 is a partial vertical section similar to that of FIGURE 7showing the device in the locked position with the handle assemblyremove-d.

As previously pointed out, most locks using sliding locking bars can beeasily burglarized by breaking off the outside handle and driving thehandle shaft through the door. This results either in release of thebars or makes accessible the operating mechanism of the lock so that itmay be forced with an appropriate tool. This forced entry is avoided bythe novel lock of this invention by the provision of a circular supporttube upon which the bolt actuating cam plate is rotatably mounted. Acircular handle shaft is rotatably received through the support tube andcarries at its inner end a lever slidably receiving a pair of pinsmounted on the cam plate.

' Hence, inward movement of the handle shaft during a forced entryattempt simply causes the ends of the lever to slide off the pins thuscompletely breaking the coupling or mechanical link-age from theexterior of the door to the cam plate.

Referring to the drawings, there is illustrated in FIG- URE 1 the novellock device of the present invention generally indicated at 10. The lock10 is mounted on a single door 11 swingable inwardly in the direction ofthe arrow 12 and supported from a wall 14 between a floor 16 and aceiling 18. Lock 10 is provided with a handle 20 rotatable from thelocked vertical position illustrated in the direction of the arrow 22 inFIGURE 2. Movement of the handle 20 reciprocates a pair of lock bars 24and 26 in the vertical direction as indicated by the arrows 23inFIGURE 1. The outer ends of the lock bars are slidably received throughlocking bar guides 28 and 30 mounted on the door and the extreme outerends of the locking bars 24 and 26 are received in suitable cavitiesprovided in the ceiling and floor as indicated by the dashed lines at 32and 34.

FIGURE 2 is an enlarged view of the lock of FIGURE 1 and similarly showswhat hereinafter will be referred to as the inside of the lockmechanism. That is the lock and door are viewed in FIGURES 1 and 2 fromthat side of the door or from the room to which access is to beprevented. In FIGURES 1 and 2, the lock is of the double custody typeand is shown provided with a pair of more or less conventional cylinderlocks 36 and 38 which by way of example only may be Yale locks. Each ofthe locks is provided with a conventional locking tongue or bolt 40 and42 respectively, the bolt 40 in FIGURE 2 being illustrated as retractedWhile bolt 42 is shown as extended into locking position in acooperating notch 44 formed on one side of a flat cam plate 46. Bolt 40of cylinder lock 36 is adapted to be received in a similar notch 48formed on the other side of the cam plate 46. In FIGURE 2, the locks 36and 38 are indicated as operable by keys from the inside as well as theoutside, normally each lock being actuated by a different key in thecustody of a different person, hence the lock is referred to as a doublecustody lock.

FIGURE 4 illustrates a single custody embodiment incorporating thesingle cylinder lock 38. In this embodiment the cam plate 46' isprovided with only the single notch 44 receiving the single bolt 42. Inall other respects the embodiment of FIGURE 4 is similar to that ofFIGURE 2.

FIGURE 3 is an exploded view showing the lock handle structure which isthe same for both single and double custody embodiments. As illustratedin the drawings and as seen in FIGURES 3-5, U-shaped inner handle 20 isprovided with a longer leg or handle shaft 49 I threaded at its outerend 50. Welded to this leg as at 52 is a cam control bar or lever 54.This lever is provided with apertures 56 and 58 at each end slidingly receiving pins 60 and 62 rigidly connected to the opposite sides of thecam plate 46 or 46 as the case may be. Each of the pins 60 and 62 isprovided with a transverse aperture receiving a cotter pin 64 and 66.The cotter pins hold washers 68 and 70 on the pins which washers retainthe ends of the pressure bars 24 and 26 rotatably mounted on the pins.

Threadedly received over the end 50 of handle shaft 49 is an outerhandle 68 retained in position between a threaded inner spacer nut 70and an outer threaded bushing nut 72.

As best seen in FIGURES 6 and 7, shaft 49 of the handle is rotatablyreceived through a hollow circular tube 74 which is secured to the dooron the outside by a retaining plate 76 and a lock nut 78. The lock nutis threadedly received over the end of the tube as illustrated at 80 inFIGURE 6. Rotatably mounted on the tube 74 is a spacer bearing 82 andwelded to the tube 74 is a retainer 84 and a mounting plate 86. Bearing82 and cam plate 46 are thus rotatably retained on the tube by thespaced plates 84 and 86, both rigidly welded to the tube. As best seenin FIGURE 2, each of the cylinder locks 36 and 38 is connected to themounting plate and to the door by four socket head screws so that theycannot be operated from the inside with a screwdriver. The penetrationof these screws through the plate 86 and into the door 11 is illustratedin dashed lines in FIGURE 6. The cylinder lock 38 is mountedapproximately flush with the outer surface 92 of the door, as indicatedgenerally at 94, and is preferably bolted to the mounting plate 86 bymeans of a pair of bolts 96 and 98 illustrated in FIG- URE 6. Themounting plate itself is secured to the door 11 by means of six screws100 and as best seen in FIG- URES 4 and 5 three of these screws arepositioned beneath or behind the cam plate 46 or 46' when the device isin the locked position so as to make access to them quite difiicult.

Referring to FIGURES 4 and 5, the former shows the unit from the insidein the locked position with the bolt 42 received in the notch 44. Theedges of the notch are turned over to form flanges 102, 104 and 106 soas to provide a larger surface against which the bolt 42 may act. Also astop pin 108 is provided on mounting plate 86 to be engaged by the camplate 46' so as to limit the rotation of this plate. When the bolt 42 ismoved to the retracted position by the insertion of a key into thecylinder lock 38 and rotation of the key therein, the cam plate 46' isfree to rotate so as to withdraw the locking bars 24 and 26 from lockingbrackets such as bracket 110 illustrated in FIGURE 4. These locking barspreferably move longitudinally a distance about an inch and a half so asto completely clear the locking brackets and permit the door :to open.Rotation of the cam plate 46' from the locked position illustrated inFIGURE 4 to the open or unlocked position illustrated in FIGURE 5 may beeffected by rotation of either the handles 20 or 68. In either case, theshaft 49 is rotated by the handle, thus rotating the lever 54. Rotationof the lever is transmitted through pins 60 and 62 to the locking bars24 and 26 and to the cam plate 46'. Rotation of either of the handles inthe opposite direction will return the elements from the open positionof FIGURE 5 to the closed position of FIGURE 4. The device may thenagain be locked by actuation of the conventional cylinder lock 38.

FIGURES 7 and' 8 illustrate the increased tamper resistance of the lockof this invention particularly to forced entry by the method of drivingthe handle actuator rod or shaft 49 through the door. FIGURE 7 is across-section showing the entire assembly while FIGURE 8 illustrateswhat is left after the handle has been removed and the shaft 49 driveninwardly through the tube 74. Inward movement of the shaft 49 throughthe tube simply causes the lever 54 to slide off the ends of pins 60 and62 and to fall to the floor. Thus, all that remains for access at theouter surface 92 of the door is the threaded end 80 of the hollow tube74. Since the central aperture of the tube indicated by the dashed linesat 112 in FIGURE 8 is circular no tool may be inserted and rotated so asto force the lock. Likewise, the nails 100 cannot be driven backwardlyfrom the outside of the door since at least three of them lie underneaththe cam plate 46' and can only be backed off until their heads engagethis cam plate.

In addition to the fact that the door provides maximum security from theoutside and limited security from the inside, it is also quite easy tooperate and will not tend to bind, become misaligned or fail to operatewith excessive wear. Rotation of either of the handles provides fordirect actuation of the retainer bars 24 and 26 by way of the pins 60and 62. The bars are retained rotatably on the pins by means of thecooperating washers and cotter keys 64 and 66. Positive locking isprovided and the device is locked with the locking bars in verticalalignment to provide a positive deadlocked arrangement. The cylinderlock 38 is retained by screws 96 and 98 thus fastening the lock cylinderdirectly to the lock mounting plate 86 so as to minimize the danger oftwisting the cylinder in the door to unlock the inside bolt.

The lock may be used with a wide variety of doors and with a widevariety of locking arrangements. These locking arrangements include:

(a) Key control from inside and outside With handle control from theinside only.

(b) Key control from the outside with a turn knob (on the lock bolt) andhandle inside.

(c) Key and handle control from inside only.

The above locking arrangements can be accomplished with no additionalaccessories to the device but instead an elimination of components shownin the drawings. For example, the arrangement (b) given above, isaccomplished by using a Yale lock of the same size and operation asshown but instead of using a key on the inside to activate the bolt aturn knob replaces the inside key. This arrangement finds use forexample in store rooms where a single door is the only Way in.

Lock arrangement (e) above involves the same basic construction as thatshown but the outside cylinder is eliminated as is the outside handle.The tubular cam plate support 74 is cut an flush with the back of themounting plate 86. Handle shaft or leg 49 is cut off just long enough toextend one-quarter inch beyond the end of the shortened cam plate,support tube 74. This end of the handle spindle may be threaded and anut attached to hold the handle within the cam plate support tube. Arelief hole is in this case drilled part way into the door toaccommodate the extending end of the handle shaft and nut. Lock mountplate 86 is screwed directly to the door as in any other typeinstallation. In this arrangement no handle is available for actuationfrom the outside and none of the door lock assembly is visible from theoutside of the door. This arrangement is ideally suited for supermarkets where back service doors are desired to be locked at all times.Obviously, if there are no handles on the outside of the door bolts theycannot be thrown to the unlocked position from the outside. Thus, if thedoor is closed and the bolts thrown, this door is in'elfect locked toanyone outside even if the key is not turned on the inside lock. Thisalso allows personnel to open and close the doors for deliveries withouthaving access to keys. In addition, it is considerably less vulnerableto outside attack since persons outside have no knowledge where the lockis located and have much more difficulty in centering an attack on thepertinent areas of thedoor. The inside handle can still be driven ortwisted off without gaining access to the inside.

FIGURE 1 shows an arrangement involving a double custody lock. This isaccomplished by extending the mounting plate 86 beyond the cam plate 46as illustrated Y in FIGURE 2 far enough to accommodate a second lock 36like the lock 38. Another slot 48 is cut in the cam plate to allow thebolt of the second lock to enter it at the opposing edge of the slot.The bolt operation, cam plate, tube and handle constructions areunchanged. This double custody arrangement of FIGURE 1 is a very specialtype arrangement having a limited demand where it is desirable to havetwo persons present when opening the lock and requiring two difierentkeys. I

By way 'of example only in one embodiment constructed in accordance withthe present invention the locking bars -24 and 26 were formed of 1" xfiat steel and had a 1 /8" throw. The guides 28 and 30 were made of 1" xVs" x 4 /2" flat steel. The bars were held away from the door A" by aguide mounting strap welded to each of the guides. The cam plate was offiat steel and carried two as" cold rolled steel pins and 62. Themounting plate was /s" x 4 /2" x 9 steel plate and the handle shaft andinside handle was a one-piece construction having a diameter of /2"formed of cold rolled steel and having an overall length of 4". In someinstances where the door material is strong enough (not for light sheetmetal or hollow core wooden doors) the support tube may be eliminatedand the cam plate may be rotatably mounted directly on the handle shaft.

It is apparent from the above that the present invention provides anovel security lock that not only increases the security of the doorupon which it is incorporated but one that is relatively simple andinexpensive, reliable in operation and one which will not bind or becomeinoperative with wear. All parts are positively connected, with thebolts and cam plates securely aligned by their mounting on a commonmounting plate.

The invention may be embodied in other specific for-ms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed-and. desired to be secured by States'Letters Patent is:1

1. A door lock comprising a mounting plate for a-tt-achment to a door, ahollow cylindrical tube passing through said mounting plate and rigidlyattached thereto, a handle shaft rotatable in said tube, a cam platerotatably mounted on said tube, locking means coupled to and actuated bysaid cam plate, key actuated means for holding said cam plate againstrotation, and means releasable upon longitudinal movement of said handleshaft in an inward direction away from said cam plate coupling saidhandle shaft to said cam plate.

2. A door lock according to claim '1 wherein said releasable meanscomprises at least one pin mounted on said cam plate, and .a leverrigidly mounted on said handle shaft, said lever having an apertureslidably received over said p-in.

United 3. A door lock comprising a mounting plate, means for attachingsaid mounting plate to a door, a hollow tube having a circular centralaperture passing through said mounting plate and rigidly attachedthereto, a handle shaft rotatable in said tube, a handle attached to atleast one end of said handle shaft, a cam plate rotatably mounted onsaid tube, said cam plate carrying at least one pin, looking meansrotatably received over said pin, key actuated means for holding saidcam plate against rotation and a- 5. A door lock according to claim '4wherein said bolt is part of a cylinder lock mounted on said mount-ingplate adjacent said cam plate.

6. A door lock comprising a mounting plate,.means for attaching saidmounting plate to a door, a hollow tube having a circular centralaperture passing through said mounting plate and rigidly attachedthereto, a handle shaft .rotatable in said tube, a handle attached to atleast one end of said handle shaft, a cam plate rotatably mounted onsaid tube, said cam plate carrying a pair of pins spaced upondiametrically opposite sides of said tube, a pair of locking bars eachhaving an end rotatably received over one of said pins, key actuatedmeans for holding said cam plate against rotation, and a lever rigidlymounted on said handle shaft, said lever having an aperture at each endslidably received over one of said pins.

7. A door lock according to claim 6 wherein said handle shaft isprovided with a handle at each end.

8. A door lock according to claim 6 wherein said key actuated meanscomprises a pair of cylinder looks mounted on said mounting plateadjacent said cam plate, each of said cylinder locks having -a slidingbolt movable into and out of engagement with a corresponding notch inthe edge of said cam plate.

9. A door lock comprising a mounting plate, means for attaching saidmounting plate to a door, a hollow tube having a circular centralaperture passing through said mounting plate and rigidly attachedthereto, a handle shaft rotatable in said tube, a handle attached to atleast one end of said handle shaft, a cam plate rotatably mounted onsaid tube, said cam plate carrying a pair of pins spaced upondiametrically opposite sides of said tube, a pair of elongated slidablelocking bars extending away from said cam plate on opposite sidesthereof, the adjacent ends of said locking bars being rotatably mountedover said pins, means for retaining said adjacent ends of said bars onsaid pins, a cylinder lock bolted to said mounting plate adjacent saidcam plate, said cylinder lock having a bolt movable into and out ofengagement with a corresponding notch in the edge of said cant plate tohold said cam plate against rotation, and a lever rigidly mounted onsaid handle shaft, said lever having an aperture at each end slidablyreceived over one of said pins.

10. A door lock according to claim 9 wherein said cam plate overlies atleast three mounting screw apertures in said mounting plate when saidcam plate is in the locked position with said bol-t engaged in saidnotch.

11. A door lock according to claim 10 wherein said locking bar retainingmeans comprises a washer on each of said pins and a cotter key passingthrough each pin,

said washers and cotter keys spacing said locking bars from said lever.

12. A door lock assembly comprising a door and surrounding door framestructure, a mounting plate secured to the inside surface of said door,a hollow tube having a circular central aperture passing through saiddoor and said mounting plate and rigidly attached to said mountingplate, a handle shaft having a handle at each end rotat ably receivedthrough said tube, a cam plate rotatably retained on said tube, said camplate carrying a pair of pins spaced upon diametrically opposite sidesof said tube, a pair of elongated slidable locking bars extending away'from said cam plate on opposite sides thereof, the adjacent ends ofsaid locking bars being rotatably mounted over said pins, means forretaining said adjacent ends of said bars on said pins, a receptacle insaid door frame structure at each end of said door, the remote ends ofsaid locking bars being slidab-le into and out of said receptacles withthe rotation of said cam plate, a cylinder lock bolted to said mountingplate adjacent said cam plate, said cylinder lock having a bolt movableinto and out of engagement with a corresponding notch in the edge ofsaid cam plate to hold said cam plate against rotation, and a leverrigid- 'ly mounted on said handle shaft, said lever having an apertureat each end slidably received over one of said pins.

13. An assembly according to claim 12 including a second cylinder lookon said mounting plate adjacent said cam plate, said second cylinderlock also having a bolt movable into and out of engagement with acorresponding notch in the edge of said cam plate.

14. An assembly according to claim 12 wherein said cylinder lock ismounted on said mounting plate by socket head screws, and wherein saidmounting plate is secured to said door by a plurality of mountingscrews, said cam plate overlying the heads of at least three of saidmounting screws when said cam plate is in the locked position.

References Cited by the Examiner UNITED STATES PATENTS 201,146 3/1878Adler 2926 1,240,981 9/1917 Kohl 1 14 1,567,811 12/1925 Murphy 70-4141,922,062 8/1933 Sullivan 70'1 14 2,819,692 1/1958 Johnson et a1 70116 X2,969,666 1/196'1 Muessel 70-116 3,173,572 3/1965 Beecher 2927 JOSEPH D.SEE-RS, Primary Examiner.

BOBBY R. GAY, Examiner.

1. A DOOR LOCK COMPRISING A MOUNTING PLATE FOR ATTACHMENT TO A DOOR, AHOLLOW CYLINDRICAL TUBE PASSING THROUGH SAID MOUNTING PLATE AND RIGIDLYATTACHED THERETO, A HANDLE SHAFT ROTATABLE IN SAID TUBE, A CAM PLATEROTATABLY MOUNTED ON SAID TUBE, LOCKING MEANS COUPLED TO AND ACTUATED BYSAID CAM PLATE, KEY ACTUATED MEANS FOR HOLDING SAID CAM PLATE AGAINSTROTATION, AND MEANS RELEASEABLE UPON LONGITUDINAL MOVEMENT OF SAIDHANDLE SHAFT IN AN INWARD DIRECTION AWAY FROM SAID CAM PLATE COUPLINGSAID HANDLE SHAFT TO SAID CAM PLATE.